Slideshow using all images from a directory?

I have a website where I want the users to be able to upload certain pictures to a predefined directory of pictures. I then want to have a slideshow using all those pictures, automatically. The upload part is already done. I've found lots of slideshow scripts on the net, but all I've found need you to load the images into an array, or to - inside the code - name all the images. Is there a way to automatically take all images in a directory and do a slideshow with them?
Any help would be great, thanks!
Peo
Mexico City

Yes, load them into an array. Then loop through them.